The present invention is generally directed to an object sorting system and, more particularly, to an object sorting system for automatically inspecting a plurality of objects.
Machine vision systems have been utilized in a variety of applications, which include food processing, metal recycling, mineral processing and paper recycling, among other applications. As is well known to one of ordinary skill in the art, vision systems are based on non-contact measurements of electromagnetic radiation (e.g., visible light, infrared light and x-rays), which are typically facilitated by a camera. In the manufacturing and processing environments, it is common to optically inspect and sort individual articles with automatic inspection systems. Many of the inspection systems have determined properties (e.g., color, size and shape) of the articles such that defective articles could be separated from good articles. Machine vision systems have been utilized, for example, to inspect fruit, vegetables and nuts. Machine vision systems have also been utilized in other areas that require a similar sorting of products and/or articles. For example, such systems have been utilized to sort wood chips, aggregates and manufactured products, such as, fasteners and formed objects, in addition to meat products, such as quartered or cubed poultry or beef products.
In a typical system, video images of the products and/or articles are captured, with a camera and a frame grabber, to extract color, shape and/or size related information. Typically, bulk articles are stabilized, using centrifugal force, and conveyed individually past an optical inspection station. In a typical prior art system that implements air deflectors, the center of a defective product is computed such that an air stream is aimed at the center of the product to remove the defective product from a product stream.
Inspection systems have also been designed to inspect various circular parts by dimension and to detect surface defects in the parts. Some of these systems have determined an inside diameter, an outside diameter and detected surface defects, such as nicks, fractures, etc. A wide variety of cameras, which include line scan cameras, area scan cameras and CMOS cameras, have been utilized or proposed for utilization in various inspection systems. Images captured by the cameras are automatically processed and evaluated such that image dependent decisions can be implemented. In prior art systems that have inspected a surface of an object, the object has generally been grasped by an apparatus, which rotates the object such that a camera can inspect the surface of the object. Unfortunately, using an apparatus that has to grasp an object to rotate the object has generally created an inspection bottleneck within such systems.
Thus, what is needed is a practical inspection system that can rotate an object that is to be inspected without seriously impacting system throughput.
The present invention is directed to an object sorting system for automatically inspecting a plurality of objects and sorting acceptable objects from defective objects. The system includes a feed conveyor, a barrier, a sorting camera, at least one rejection valve and a processor. The feed conveyor receives a plurality of objects and moves the objects through an inspection area. The barrier is placed across a top surface of the feed conveyor and defines a boundary of the inspection area. The barrier is configured to redirect the plurality of objects and, in conjunction with the feed conveyor, cause the objects to rotate about an object axis. The sorting camera is positioned for capturing an image of each of the plurality of objects as the objects rotate and move through the inspection area. The at least one rejection valve functions to direct a finally defective object, such that the finally defective object is separated from inspected acceptable objects. In one embodiment, the processor, which is coupled to the feed conveyor, the sorting camera and the at least one rejection valve executes an inspection routine that controls the speed of the feed conveyor, scanning rate of the sorting camera, and actuation of the at least one final rejection valve. According to another embodiment of the present invention, the barrier includes at least one pair of substantially parallel wires that contain the plurality of objects.
These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.